Coupling Relationships of Water-Food-Carbon Coupling System in Yangtze River Basin, China

A greater understanding of the interactions among water, food, and carbon is needed to promote the sustainable development of the Yangtze River Basin (YRB), China. In this study, we calculated the water yield (WY), food supply (FS), and carbon sequestration (CS) services of the YRB in 2000, 2010, and 2020 via the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model. Then, we used the correlation coefficient and spatial clustering methods to analyse the coupling relationships among WY, FS, and CS. Finally, we identified the main factors of the water-food-carbon (WFC) coupling system via the optimal parameter geographic detector. The results showed that WY, FS, and CS in the YRB have degraded from 2010 to 2020 with reductions of –6.30%, –0.13%, and –0.31%, respectively. A notable trade-off relationship existed between FS and CS, with correlation coefficients of –0.63 in 2000, –0.62 in 2010, and –0.60 in 2020. From 2000 to 2020, the area proportion of the grassland low-service bundle decreased from 28.18% to 25.05%, whereas that of the ecologically balanced bundle increased from 23.24% to 24.85%. Distance to cropland, distance to forested land, and land use were the main driving factors for the WFC coupling system in the YRB, with explanatory power of 0.72, 0.43, and 0.87 in 2010, respectively. These findings provide scientific theoretical support for achieving food security, water security, carbon neutrality and peak carbon goals in the YRB.